Oxygen-Effect in Annealing of Recoil Damage in Cobalt Chelates-Tris-Acetyl-Acetone Co(III) and Bis-Salicylaldehyde Triethylenetetramine Co(III) Chloride

1964 ◽  
Vol 3 (3) ◽  
Author(s):  
Amar Nath ◽  
K. Annaji Rao ◽  
V. G. Thomas
Keyword(s):  
Kinetic Data ◽  
Isothermal Annealing ◽  
Cobalt Atom ◽  
Cobalt Complexes ◽  
Electron Trap ◽  
Oxygen Effect ◽  
Variable Depth ◽  
Deep Electron Trap ◽  
Annealing Kinetic ◽  
Cobalt Chelates

SummaryA marked 'oxygen effect' is observed for several cobalt complexes in thermal annealing. Kinetic data are reported for recoil damage, afterIt is suggested that during an isothermal annealing run electrons are released from variable depth traps, and interact with the metastable species (damage centres) formed by virtue of interaction of recoil cobalt atom with a chelate molecule. The adsorbed oxygen on the surface acts as deep electron trap and suppresses annealing. Once it is displaced by N

Properties of the EL2 Level in Organometallic Ga1−xAlxAs

1987 ◽  
Vol 104 ◽  
Author(s):  
A. Ben Cherifa ◽  
R. Azoulay ◽  
G. Guillot
Keyword(s):  
Vapor Deposition ◽  
Deep Level Transient Spectroscopy ◽  
Metalorganic Chemical Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Electron Trap ◽  
Quenching Effect ◽  
Deep Electron Trap ◽  
Transient Spectroscopy ◽  
First Time

ABSTRACTWe have studied by means of deep level transient spectroscopy and photocapacitance measurements deep electron traps in undoped Ga1−xAlxAs of n-type grown by metalorganic chemical vapor deposition with 0≤x≤ 0.3. A dominant deep electron trap is detected in the series of alloys. Its activation energy is found at EC-0.8 eV in GaAs and it increases with x. Its concentration is found nearly independent of x. For the first time we observed for this level in the Ga1−xAlxAs alloys, the photocapacitance quenching effect typical for the EL2 defect in GaAs thus confirming clearly that EL2 is also created in MOCVD Ga1−xAlxAs.

Bivalent cobalt complexes of 2,4,6-Tri(2'-pyridyl)-1,3,5-triazine

1969 ◽  
Vol 22 (1) ◽  
pp. 141 ◽  
Author(s):  
RN Warrener ◽  
EC Watton
Keyword(s):  
Room Temperature ◽  
Magnetic Moments ◽  
Cobalt Atom ◽  
Cobalt Complexes ◽  
Octahedral Complex ◽  
Tetrahedral Coordination ◽  
Temperature Moment ◽  
Single Exception ◽  
Dimeric Form ◽  
Thermogravimetric Studies

This paper reports the isolation of a series of new coordination compounds formed with the terdentate ligand 2,4,6-tri(2?-pyridyl)- 1,3,5-triazine (tpt) and various bivalent cobalt salts. The stereochemistries of these compounds are proposed after consideration of their elementary analyses, visible solid and solution spectra, infrared spectra, magnetic moments, and thermogravimetric studies. ��� The chelates obtained include octahedral bis-complexes of the type [Co tpt2]X2 (where X = Cl, Br, I, CNS, ClO4, NO3, BF4, or BPh4) and five- coordinate mono-complexes of the type CoXz tpt (where X = Cl, Br, I, or NCS). A third dimeric form is also reported of general formula Co2X4 tpt,nH2O (where X = Cl, n = 0 or I; X = Br, n = 0 or 2). In this latter form the ligand appears to function as a composite of both terpyridine and bipyridine, showing simultaneous terdentate and bidentate behaviour, with one cobalt atom in either a five-coordinate or six- coordinate environment, and the other metal atom involved in tetrahedral coordination. ��� In general the compounds formed are high-spin with normal room- temperature magnetic moments. The single exception is the red octahedral complex [Co tpt2]Cl2, 8.5H2O, which has a room-temperature moment of only 4.0 B.M.

Thio derivatives of β-Diketones and their metal chelates. XV. Mass spectra of cobalt(III) and rhodium(III) chelates of some fluorinated Monothio-β-diketones

1974 ◽  
Vol 27 (6) ◽  
pp. 1177 ◽  
Author(s):  
M Das ◽  
SE Livingstone
Keyword(s):  
Thermal Degradation ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Cobalt Complexes ◽  
Metal Chelates ◽  
Complex Ions ◽  
Molecular Ion ◽  
Derivatives Of ◽  
Bivalent State ◽  
Cobalt Chelates

The mass spectra of the cobalt(111) and rhodium(111) chelates of the fluorinated monothio-β-diketones RC(SH)=CHCOCF3 (R = Ph, p-MeC6H4, p-BrC6H4, p-FC6H4, and 2-thienyl) and of the cobalt(111) chelate of CH3C(SH)=CHCOCF3 have been obtained. The cobalt chelates do not give a peak for the molecular ion because of thermal degradation to the cobalt(11) complex CO(RCS=CHCOCF3)2, which then undergoes reactions in the mass spectrometer. Fluorine migration occurs with cobalt but not with rhodium. The cobalt complexes give rise to more metal-containing fragments than their rhodium analogues. Mechanisms are proposed for the reactions involving the metal-containing fragments. Cobalt undergoes valency changes to give cobalt(11) and cobalt(1) complex ions, whereas rhodium undergoes a valency change to the bivalent state only.

Synthesis, Characterization, and Ethylene Oligomerization of 2,6-Bis(imino)phenoxy Cobalt Complexes

2003 ◽  
Vol 56 (7) ◽  
pp. 703 ◽  
Author(s):  
Jianlong Du ◽  
Lingqin Han ◽  
Yong Cui ◽  
Jitai Li ◽  
Yan Li ◽  
...  
Keyword(s):  
Cobalt Atom ◽  
Cobalt Complexes ◽  
Ethylene Oligomerization ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Imino Nitrogen ◽  
Catalytic Activities ◽  
Elemental Analyses ◽  
Molar Equivalent ◽  
Cobalt Dichloride

A series of cobalt complexes bearing 2,6-bis(imino)phenoxy ligands were synthesized by treating the ligand 2,6-bis(imino)phenol with a molar equivalent of cobalt dichloride. These complexes were characterized by elemental analyses and IR spectroscopy. The structure of the resulting complex was determined by single-crystal X-ray diffraction; it crystallizes in the monoclinic space group C2/c, with a 22.313(3) Å, b 14.7078(15) Å, c 17.7652(17) Å, β 107.96(7)°, and V 5546.0(10) Å3. The coordination geometry around the cobalt atom can be described in terms of a distorted tetrahedral bonded with one phenoxy oxygen, one imino nitrogen, and two chloride atoms. In the presence of a methylaluminoxane cocatalyst, this and related complexes displayed catalytic activities towards ethylene oligomerization.

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